Breath analyzing devices are used to determine the blood alcohol content of those who blow into the devices. These devices have become increasing popular with the increased effort by law enforcement to reduce drunk driving. While the traditional use of the breath analyzing devices has been by law enforcement officers to test a suspected intoxicated driver, the breath analyzing devices now are being used in combination with an ignition locking system to prevent an intoxicated driver from being able to start the vehicle.
The devices typically require the driver to blow into the breath analyzing device prior to starting the car. If the driver's breath alcohol level is below a predetermined level, the car will start. However, if the driver's breath alcohol level is too high, the car will not start. Drivers typically use breath analyzing devices in combination with ignition locking systems in one of two situations. The first situation is when ordered to do so by a court. Courts are finding these systems to be effective in controlling drivers with multiple incidents of driving while intoxicated. The second situation is voluntary use by drivers concerned about driving or getting apprehended while driving under the influence of alcohol. Additional uses such as in commercial fleets, taxis, buses and the like also offer a suitable environment for these types of systems.
The most commonly used alcohol sensor is the gas detection tube. However, a better alcohol sensor is the fuel cell. The fuel cell is a more accurate device for measuring the alcohol content in a breath sample. Thus there is a need for a breath analyzer which utilizes a fuel cell.
The alcohol sensing devices are typically very sensitive to temperature. Various attempts have been made to minimize the effect temperature change, especially as the alcohol sensor gets colder, has on the accuracy of the reading. A previously tried method allowed the sensor to get cold and then attempted to compensate the result utilizing an algorithm dependent upon temperature. Other approaches warm the breath analyzer to keep the alcohol sensor warm. This is costly in terms of energy consumption. Thus there is a need for a combination alcohol sensor and heating mechanism which effectively and efficiently maintains the alcohol sensor in a temperature range so as not to jeopardize reliability.
The output of alcohol sensors are prone to vary due to several factors. Time, temperature and other environmental conditions can all cause the output of the alcohol sensor to be inaccurate. Thus there is a need for a compensating algorithm which accurately compensates the output of an alcohol sensor.
In light of the foregoing, an improved breath analyzing device used in combination with an ignition locking system is needed which utilizes a highly accurate alcohol sensor, which delivers a precise amount of breath sample to the alcohol sensor, which does not require mathematical corrections to compensate for the drop in ambient temperature, and which requires the user to perform rolling retests while operating the vehicle.